According to results from the PESA CNIC- Santander Study recently published in the Journal of the American College of Cardiology, both not getting enough sleep (less than 6 hours a night on average in this Spanish study) and suffering through frequently-disrupted sleep (in which a person wakes up several times a night) are linked to a significantly higher risk of plaques in the cardiovascular system which should eventually result in a higher risk of heart attacks, strokes and sudden death from either of those sleep problems.
This was a good study of 4000 people, average age 46, who were free of heart disease at the start of the study, and it showed that compared to the excellent sleepers, the short-sleepers had a 27 % higher risk of plaque development, while those with disrupted sleep had a 34 % higher risk.
The researchers did not measure an actual increase in the rate of heart attacks and strokes in the study participants since the study was too short to come up with good numbers but we can presume a higher risk of those eventual consequences because other studies have clearly linked cardiovascular plaque to more heart and stroke troubles.
Interestingly too in this study, although their number was too small to really make much sense of it, the trend showed that those who slept more than 8 hours a night on average also had a higher risk of cardiovascular plaque development over the course of the study.
So is lack of good sleep really a major risk factor for heart attack and stroke all on its own?
Maybe, or maybe not (I know, I know, it’s a disappointing answer but I can only tell it like it ought to be).
The most important mitigating factor in this link between poor sleep and cardiovascular (CV) problems is that lack of sleep may simply be a marker for other (perhaps more important) health issues in those people, and its those other health issues – stress level differences, economic differences, early lifestyle factors, diet, rest, daytime habits, coffee intake, alcohol use, other drugs – that are perhaps more important as to why people who can’t or won’t sleep more than 6 hours a night seem to develop more CV disease.
In other words, no matter how much the researchers try to account for those other factors in such studies, they are rarely able to put that vital issue – whether poor sleep is a marker for or a cause of CV problems – to bed (as it were).